Great chicken chill debate: Air vs. water

In the world of poultry, natural, free-range and organic have become all-too familiar labels. Now, look for another one at high-end grocery stores near you: air-chilled.

The air-chilling process, common in Western Europe for more than 45 years, is still fairly new in the United States. It refers to a specific method used to cool chickens after slaughtering. Most chickens in this country are processed by being immersed in ice water. By contrast, air-chilling cools chickens by blasting them with cold air.

Air vs. water? Is there really such a huge difference?

Many retailers think so. Since January, Whole Foods has been steadily converting all of its full-service meat counters in Northern California to sell only air-chilled chicken. And Niman Ranch, known for its sustainable and humanely raised meats, is starting to sell an air-chilled French heritage chicken called Poulet Rouge Fermiere. It is the company's first chicken product.

"I do prefer this type of chicken. Whenever I can find them, I buy them," says San Francisco food scientist Harold McGee, author of the fundamental On Food and Cooking: The Science and Lore of the Kitchen (Scribner, 2004), who became a fan of air-chilled chicken when he lived in France.

"The basic fact that you're not adding anything extraneous to the chicken is the most important to me. If you're buying chicken, you want chicken - not chicken with ice water."

Fans of air-chilled chicken, which carries a retail price close to that of organic chicken, tout its top selling points: safety and flavor, along with texture.

Because air-chilled chickens are handled separately, rather than placed together into a large vat of ice water, proponents believe these chickens are apt to harbor less bacteria from cross-contamination. Studies, however, have not always concurred.

Supporters also believe air-chilled poultry tastes more "chickeny." Because air-chilled chicken isn't ever submerged in water, it absorbs less liquid, which fans say leaves the real taste of the chicken undiluted.

In comparison, studies have shown that water-chilled chicken sucks up anywhere from 2 percent to 12 percent of its weight on average in added moisture. And most of that ends up in the skin, McGee says, making it much more difficult to achieve a crisp bird when cooking.

I found that to be the case when I roasted a Fulton Valley Farms organic chicken side by side with a Field to Family air-chilled chicken. Both chickens were raised on similar diets by the same group of Central Valley family ranchers.

Uncooked, the Fulton Valley chicken looked glossier and plumper, while the air-chilled had a more matte appearance with tighter skin. After roasting, both birds emerged juicy. But the air-chilled had much crisper skin and firmer flesh.

As for taste, it was a close call. The air-chilled might have had an iota more flavor, but I knew which bird was which. My husband, who tasted them blind, thought both chickens were equally flavorful.

When it comes to chicken in this country, our appetite has been relentless. Per capita consumption has been growing steadily since 1970. In 2006, according to the U.S. Department of Agriculture, the average person consumed 88.2 pounds of chicken.

Of about 200 chicken processing plants in the United States, only a handful use the air-chill method, according to Richard Lobb, spokesman for the Washington-based National Chicken Council, a trade group for the nation's largest chicken companies.

After a chicken is slaughtered, the USDA requires that the carcass temperature be lowered within four hours to at least 40 degrees to retard the growth of bacteria. For the majority of chicken in this country, that means water chilling. The birds are put into a large communal vat of chlorinated ice water to bring down their body temperature - about an hourlong process.

In contrast, air-chilling takes about three hours. After the chickens are slaughtered, and sprayed with chlorinated water inside and out, they are whisked one by one along a mile or more of track through chambers in which they are misted with cold air.

Air-chilling saves water, but it does result in higher electricity costs. Whether air-chilled chicken is safer is not really clear.

Comparing methods

A USDA-sponsored study by the University of Nebraska in 2000 found that 350 air-chilled chickens had about 20 percent less bacteria (such as salmonella and campylobacter) than the same number of water-cooled poultry. That study, though, examined only one air-chilling plant and one water-immersion plant.

In January 2008, Consumer Reports found that of 28 store-bought, air-chilled chickens processed by Pennsylvania's Bell & Evans, five had salmonella and 19 had campylobacter. (Both bacteria can cause illness, and both are killed by cooking. Chicken should be cooked to an internal temperature of at least 165 degrees.)